Can Mandated BCG Vaccine Promote herd Immunity against Novel Coronavirus? A Potential Solution at Hand to Tackle Covid-19 Pandemic

The 2019 novel coronavirus (2019-nCoV) infection is an emerging pandemic that poses a severe threat to global public health. This pandemic started from the Wuhan City of Hubei Province in China, and is speculated to have originated from bats and spread among humans with an unknown intermediate transmitter. The virus binds to angiotensin-converting enzyme 2 (ACE2), which is abundantly expressed on various human cells, including lung epithelial and intestinal cells, thereby entering into these cells and causing infection. It is transmitted to other humans through airborne droplets from infected patients. Presently there are no specific treatments or vaccines that are available to curtail the spread of this disease. There are few indirect reports that explain the potential importance of the mandated BCG vaccine as a protective factor against COVID-19. There is a speculation that a live attenuated vaccine (BCG vaccine) can be beneficial against COVID-19 to develop the initial immune response, and can also spread in the community, thereby boosting herd immunity to fight against COVID-19. This review summarizes the conclusions of various reports on the BCG vaccine, and is an attempt to establish BCG-vaccination mediated herd immunity as an effective instant intermediate approach in curbing COVID-19 spread in highly populous countries.